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 A215417 Primes that remain prime when a single zero digit is inserted between any two adjacent digits. 29
 11, 13, 17, 19, 37, 41, 53, 59, 61, 67, 71, 79, 89, 97, 109, 113, 131, 149, 191, 197, 227, 239, 269, 281, 283, 337, 367, 379, 383, 401, 421, 449, 457, 499, 503, 509, 587, 607, 673, 701, 719, 727, 739, 757, 809, 811, 887, 907, 929, 991, 1009, 1061, 1093, 1103 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Giovanni Resta, Table of n, a(n) for n = 1..4300 (terms a(1)-a(372) from Paolo P. Lava, terms a(373)-a(700) from Vincenzo Librandi) EXAMPLE 399617 is prime and also 3996107, 3996017, 3990617, 3909617, 3099617. MAPLE A215417:=proc(q) local a, b, c, i, n, ok; for n from 5 to q do   a:=ithprime(n); b:=0; while a>0 do b:=b+1; a:=trunc(a/10); od;   a:=ithprime(n); ok:=1;   for i from 1 to b-1 do     c:=a+9*10^i*trunc(a/10^i); if not isprime(c) then ok:=0; break; fi;   od;   if ok=1 then print(ithprime(n)); fi; od; end: A215417(1000); MATHEMATICA Select[Prime[Range[5, 200]], And@@PrimeQ[Table[FromDigits[Insert[ IntegerDigits[ #], 0, n]], {n, 2, IntegerLength[#]}]]&] (* Harvey P. Dale, Feb 23 2014 *) PROG (PARI) is(n)=my(v=concat([""], digits(n))); for(i=2, #v-1, v[1]=Str(v[1], v[i]); v[i]=0; if(i>2, v[i-1]=""); if(!isprime(eval(concat(v))), return(0))); isprime(n) \\ Charles R Greathouse IV, Sep 26 2012 CROSSREFS Cf. A159236, A069246, A215419-A215421. Sequence in context: A050674 A164329 A159236 * A249376 A068155 A271367 Adjacent sequences:  A215414 A215415 A215416 * A215418 A215419 A215420 KEYWORD nonn,base AUTHOR Paolo P. Lava, Aug 10 2012 STATUS approved

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Last modified October 18 05:07 EDT 2019. Contains 328145 sequences. (Running on oeis4.)